1. Field of the Invention
The present invention relates to a photoelectric converter utilized, for example, as a solar cell and more particularly to an improvement in the thin film semiconductor photoelectric converter.
2. Description of the Background Art
A thin film semiconductor photoelectric converter generally includes, as its basic structure, a first electrode layer, a photoelectric conversion layer formed of a semiconductor film, and a second electrode layer, which are laminated on a substrate. In order to attain high efficiency of photoelectric conversion in the thin film photoelectric converter, therefore, light has to be efficiently absorbed and converted into electric energy in the photoelectric conversion layer formed of a thin semiconductor film.
In the thin film photoelectric converter utilized as a solar cell, the efficiency of photoelectric conversion has recently been improved by diffusing light directed into the photoelectric conversion layer and by confining the light inside the layer (light confinement effect). In order to cause the light confinement effect, an electrode layer which has a surface texture including fine unevenness and which is formed of transparent conductive tin oxide (SnO.sub.2) and so on, for example, is formed on a glass substrate (see Japanese Patent Laying-Open Nos. 8-18084 and 7-115216, for example). The light directed into the photoelectric converter is scattered by the surface texture of the electrode layer and confined inside the semiconductor photoelectric conversion layer. In short, most of the light directed into the photoelectric converter is efficiently absorbed and converted into electric energy in the semiconductor layer and therefore a high density of short-circuit current can be attained.
Here, the electrode layer of transparent conductive oxide having a surface texture is generally formed by controlling deposition conditions in the sputtering method or the CVD method. However, it is not easy to form a transparent electrode layer having a surface texture which includes unevenness having such height differences that cause an enough light confinement effect by the sputtering method or the CVD method.